// Simple command-line kernel monitor useful for
// controlling the kernel and exploring the system interactively.

#include <inc/stdio.h>
#include <inc/string.h>
#include <inc/memlayout.h>
#include <inc/assert.h>
#include <inc/x86.h>

#include <kern/console.h>
#include <kern/monitor.h>
#include <kern/kdebug.h>

#define CMDBUF_SIZE	80	// enough for one VGA text line


struct Command {
	const char *name;
	const char *desc;
	// return -1 to force monitor to exit
	int (*func)(int argc, char** argv, struct Trapframe* tf);
};

static struct Command commands[] = {
	{ "help", "Display this list of commands", mon_help },
	{ "kerninfo", "Display information about the kernel", mon_kerninfo },
	{ "backtrace", "Display the backtrace", mon_backtrace },
};
#define NCOMMANDS (sizeof(commands)/sizeof(commands[0]))

unsigned read_eip();

/***** Implementations of basic kernel monitor commands *****/

int
mon_help(int argc, char **argv, struct Trapframe *tf)
{
	int i;

	for (i = 0; i < NCOMMANDS; i++)
		cprintf("%s - %s\n", commands[i].name, commands[i].desc);
	return 0;
}

int
mon_kerninfo(int argc, char **argv, struct Trapframe *tf)
{
	extern char _start[], etext[], edata[], end[];
	extern char bootstack[], bootstacktop[];

	cprintf("Special kernel symbols:\n");
	cprintf("  _start %08x (virt)  %08x (phys)\n", _start, _start - KERNBASE);
	cprintf("  etext  %08x (virt)  %08x (phys)\n", etext, etext - KERNBASE);
	cprintf("  edata  %08x (virt)  %08x (phys)\n", edata, edata - KERNBASE);
	cprintf("  end    %08x (virt)  %08x (phys)\n", end, end - KERNBASE);
	cprintf("Global kernel symbols:\n");
        cprintf("  vpt          0x%08x (virt) 0x%08x\n", vpt, vpt - KERNBASE);
        cprintf("  vpd          0x%08x (virt) 0x%08x\n", vpd, vpd - KERNBASE);
        cprintf("  bootstack    0x%08x (virt) 0x%08x\n", bootstack, bootstack - KERNBASE);
        cprintf("  bootstacktop 0x%08x (virt) 0x%08x\n", bootstacktop, bootstacktop - KERNBASE);
	cprintf("Kernel executable memory footprint: %dKB\n",
		(end-_start+1023)/1024);
	return 0;
}

int
mon_backtrace(int argc, char **argv, struct Trapframe *tf)
{
        // Your code here.
        uint32_t ebp, eip, arg1, arg2, arg3;
        int i;
	struct Eipdebuginfo info;

        ebp = read_ebp();
        eip = *((uint32_t*)ebp+1);
        arg1 = *((uint32_t*)ebp+2);
        arg2 = *((uint32_t*)ebp+3);
        arg3 = *((uint32_t*)ebp+4);

        do {  
                debuginfo_eip(eip , &info);

                cprintf("%s:%d: " , info.eip_file , info.eip_line);
                for( i=0 ; i<info.eip_fn_namelen ; i++)
                        cprintf("%c" , info.eip_fn_name[i]);

                cprintf("+%x\n", eip-info.eip_fn_addr);		
                cprintf("ebp 0x%x eip 0x%x args 0x%x 0x%x 0x%x\n", ebp, eip, arg1, arg2, arg3);

                ebp = *((uint32_t*)ebp);
                if (ebp != 0) {
                        eip = *((uint32_t*)ebp+1);
                        arg1 = *((uint32_t*)ebp+2);
                        arg2 = *((uint32_t*)ebp+3);
                        arg3 = *((uint32_t*)ebp+4);
                }
        } while (ebp != 0);
        return 0;
}



/***** Kernel monitor command interpreter *****/

#define WHITESPACE "\t\r\n "
#define MAXARGS 16

static int
runcmd(char *buf, struct Trapframe *tf)
{
	int argc;
	char *argv[MAXARGS];
	int i;

	// Parse the command buffer into whitespace-separated arguments
	argc = 0;
	argv[argc] = 0;
	while (1) {
		// gobble whitespace
		while (*buf && strchr(WHITESPACE, *buf))
			*buf++ = 0;
		if (*buf == 0)
			break;

		// save and scan past next arg
		if (argc == MAXARGS-1) {
			cprintf("Too many arguments (max %d)\n", MAXARGS);
			return 0;
		}
		argv[argc++] = buf;
		while (*buf && !strchr(WHITESPACE, *buf))
			buf++;
	}
	argv[argc] = 0;

	// Lookup and invoke the command
	if (argc == 0)
		return 0;
	for (i = 0; i < NCOMMANDS; i++) {
		if (strcmp(argv[0], commands[i].name) == 0)
			return commands[i].func(argc, argv, tf);
	}
	cprintf("Unknown command '%s'\n", argv[0]);
	return 0;
}

void
monitor(struct Trapframe *tf)
{
	char *buf;

	cprintf("Welcome to the JOS kernel monitor!\n");
	cprintf("Type 'help' for a list of commands.\n");


	while (1) {
		buf = readline("K> ");
		if (buf != NULL)
			if (runcmd(buf, tf) < 0)
				break;
	}
}

// return EIP of caller.
// does not work if inlined.
// putting at the end of the file seems to prevent inlining.
unsigned
read_eip()
{
	uint32_t callerpc;
	__asm __volatile("movl 4(%%ebp), %0" : "=r" (callerpc));
	return callerpc;
}
